The cost of fuel for heating systems employing a furnace and ducts to convey the heated air throughout the occupied spaces has resulted in a return to free-standing heating units which can utilize wood or coal. Since these free-standing heatings units are made of steel or iron, they have become, by necessity, very hot during the burning of the fuel on the interior thereof. As a result, most manufacturers issue instructions regarding the use of a heat resistant material not only under the heating units but also on vertical surfaces adjacent to them. Very often the manufacturer specifies that the heating unit must be a certain distance from vertical surfaces if protective materials are not utilized. Building codes in most parts of the country wherein the free-standing units are used also contain regulations concerning the placement of the heating units.
While the free-standing heating unit provides heat by means of conversion from the heating unit itself, and to a certain extent from the ducts which lead from the stove to a chimney, many devices have been developed to increase the amount of heat which can be radiated into the room, particularly from the exhaust duct so as to recover more heat from the energy. These units generally are inserted into the duct and exhaust from the free-standing heat unit will either pass through several channels in the heat-enhancing unit, or draw air from the room to pass through other channels where it is heated by the temperature of the exhaust duct. Very often these radiation enhancers are also equipped with a small fan which increases the volume of air which can be passed through the radiation enhancing unit. Other devices include multi-fanned elements which may be clamped about the exhaust duct.
Generally speaking, these radiation enhancing units will provide increased radiation but do not provide any protection for the vertical surfaces adjacent to the free-standing heating unit. In many instances the use of heat resistant materials on the vertical surfaces is unattractive and not desired because of the particular decor of the room in which the heating unit is placed. This then necessitates moving the free-standing heating unit away from vertical surfaces out into the room where it is more noticeable and can only interfere with the generally normal arrangement of furniture and rugs and so forth in an occupied space.